Recently, electronic products have various functions and superior performance and have tended toward the small-size and light-weight. In order to realize the electronic products having the small-size and light-weight, the size or volume of parts installed in the electronic products must be reduced.
In particular, as the semiconductor integrated circuits have been developed, circuits can be prepared with the small-size and light weight. However, there is a problem to reduce the volume of an inductor installed in the electronic products. In this regard, studies and research have been continuously performed to reduce the size and the weight of the inductor installed in the electronic product.
Meanwhile, a PFC (Power Factor Correction) converter, which is an input power factor correction circuit, has been extensively used for a power supply apparatus of the electronic product in response to the demand for reducing harmonics and correcting input power factor in commercial power.
In addition, in order to reduce the ripple of input current Iin and to improve the efficiency of the PFC converter, an interleaved PFC converter (or interleaved boost converter) employing two individual inductors has been used.
To this end, according to the related art, an air gap is essentially required in an intermediate magnetic path or a lateral magnetic path of a core to manufacture a couple inductor. However, in order to form the air gap, an additional cutting work is necessary, so the manufacturing cost may be increased and the management for the air gap may be difficult.